The present invention relates to a method and equipment for implementing electronic cash through utilization of an electrical communication system, or a smart card or the like which records information.
Conventional electronic cash techniques or schemes are disclosed, for example, in Japanese Patent Publication 7-052460 entitled xe2x80x9cMethod and Apparatus for Implementing Electronic Cash,xe2x80x9d Japanese Patent Application Laid-Open Nos. 4-367070 entitled xe2x80x9cElectronic Cash Implementing Method,xe2x80x9d 5-20344 entitled xe2x80x9cElectronic Cash Implementing Method,xe2x80x9d 7-302288 entitled xe2x80x9cElectronic Cash System,xe2x80x9d 8-87559 entitled xe2x80x9cElectronic Cash Implementing Method and Electronic Cash System,xe2x80x9d and 9-128465 entitled xe2x80x9cElectronic Cash Implementing Method with A Trustee.xe2x80x9d
In these electronic cash schemes proposed so far, electronic cash is attached with a signature of an electronic cash issuing institution (hereinafter referred to also as an issuer) for information which specifies the user of the electrnic cash and the amount of money issued. The user stores the issued electronic cash in user equipment, and for each purchase, sends the electronic cash to a shop in a required amount. The shop makes a check to see if the electronic cash sent thereto is affixed with a valid signature, and if so, receives the electronic cash. The receiver, that is, the shop returns electronic cash information to the issuer for conversion. The issuer verifies the electronic cash information returned thereto to check for an improper use.
With the conventional electronic cash schemes mentioned above, the issuer manages information for each issuance of electronic cash, and the issued electronic cash returns via the user and the shop to the issuer, which checks the electronic cash for improper use. This method has such disadvantages as listed below.
The user is required to have a storage device for holding electronic cash issued to him.
The receiver, a bank and the electronic cash issuer are each required to have a device and time for verifying electronic cash.
The issuer is required to have a particularly large-capacity storage for storing information corresponding to electronic cash issued.
Since the user specifying information (pseudonym) is determined at the time of issuance of electronic cash, it cannot be changed to a different pseudonym when the user makes a payment by electronic cash.
It is therefore an object of the present invention to provide an electronic cash implementing method and equipment which dispense with storage devices for the storage of electronic cash by enabling users to make payments with their signatures alone and by making a check in an electronic cash issuing institution for an improper user of electronic cash for each user and, moreover, provide increased security for user privacy by allowing the users to use different pseudonyms for requesting the issuance of electronic cash and for making payments to shops.
The issuer equipment has a balance counter for each user, issues electronic cash in response to a request from user equipment, then increments the balance counter by the amount of electronic cash issued, and upon receiving electronic cash returned thereto, decrements the balance counter by the amount returned.
The user has a balance counter in user equipment, and upon receiving electronic cash issued from the issuer, increments the balance counter by the amount of issue. Upon making a payment by electronic cash, the user decrements the balance counter by the amount paid. The user is allowed to make payments by his signature until the balance counter goes down to zero.
Shop equipment makes a check to see if the user signature is valid, and if so, receives the payment, stores the user signature, and returns it to the issuer equipment for conversion.
With the above scheme according to the present invention, the user equipment is enabled to render payment without the need to have a storage for storing electronic cash. The issuer equipment is capable of managing electronic cash information by the balance counter, and hence does not need to store the information. Moreover, since the user is allowed to selectively use any one of a plurality of user signatures when he makes a payment, his privacy can be protected with much ease.